KR101390533B1 - Positive electrode active material for non-aqueous electrolyte secondary battery and process for production thereof, and non-aqueous electrolyte secondary battery produced using the positive electrode active material - Google Patents

Abstract

The present invention provides a non-aqueous electrolyte secondary battery having high charge and discharge capacity and capable of attaining both safety and durability characteristics.
The positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention is a lithium nickel composite oxide to which at least two or more kinds of metal elements including aluminum are added, and fine secondary particles having an average particle diameter of 2 to 4 μm and an average particle diameter of 6 to 15 μm. Aluminum particles (metal molar ratio; SA) of the fine secondary particles, wherein the aluminum content (metal molar ratio; LA) of the fine secondary particles is included; ), And the aluminum concentration ratio (SA / LA) is preferably in the range of 1.2 to 2.6.

Description

A positive electrode active material for a non-aqueous electrolyte secondary battery, a method of manufacturing the same, and a non-aqueous electrolyte secondary battery using the positive electrode active material TECHNICAL FIELD PRODUCED USING THE POSITIVE ELECTRODE ACTIVE MATERIAL}

The present invention relates to a non-aqueous electrolyte secondary battery and a cathode active material including a cathode active material, in particular lithium nickel composite oxide, used as the cathode material thereof.

Lithium ion secondary batteries, which are nonaqueous electrolyte secondary batteries, are small and have a high capacity, and thus are mounted as power sources for small mobile devices such as mobile phones, video cams, and portable information terminals (PDAs). In addition, research and development of large-sized lithium ion secondary batteries are also in progress, with the goal of mounting them in automobiles represented by hybrid cars. From this background, although higher capacity and output characteristics are required for a lithium ion secondary battery, especially the life expectancy characteristic which can be used over a longer period of time compared with a civilian use is especially the case for a lithium ion secondary battery for automobile use. It is required.

Lithium nickel composite oxide (LNO), which is one of the positive electrode materials of lithium ion secondary batteries, has a higher capacity than the current mainstream lithium cobalt composite oxide (LCO), and nickel (Ni) as a raw material is cheaper than cobalt (Co). Since it has the advantage that it can be obtained stably, it is anticipated as a next-generation positive electrode material, and its research and development continue actively.

However, lithium nickel composite oxides have low crystal stability and pose problems in cycle characteristics and thermal stability.

In order to solve such a subject, improvement of the battery characteristic by various additional elements is examined. For example, Patent Document 1 proposes to improve the durability by adding Co to LiNiO ₂ . However, even in a battery having the most durability, its capacity is reduced by half in about 500 cycles, and its durability is insufficient when a vehicle is used.

On the other hand, as an improvement by concentration distribution of an additional element, Patent Document 2 selects from the group consisting of LiCoO ₂ cores and Al, Mg, Sn, Ca, Ti, and Mn for the purpose of improving cycle stability by improving structural stability. Disclosed is a positive electrode active material for a lithium ion secondary battery, comprising a metal, wherein the metal is distributed at different concentration gradients from the surface layer to the center of the core. However, this positive electrode active material for lithium ion secondary batteries is aimed at improving the cycle stability of the battery, and no consideration is given to the improvement of the safety of the battery. Moreover, application to lithium nickel complex oxide is not considered, and the effect is also unclear.

Patent Literature 3 discloses that Co and Al are present inside the particles in order to improve the safety of the lithium nickel composite oxide, the concentration of Mn has a concentration gradient with respect to the radial direction of the particles, and Lithium nickel composite oxide is proposed which has a high concentration. However, in the battery using this lithium nickel composite oxide, a resistance increase due to storage of 7% or more occurs in one week, and the durability thereof is insufficient when a vehicle is used.

As described above, although lithium ion secondary batteries have high expectations as large secondary batteries used especially for power sources for hybrid vehicles and electric vehicles, it is particularly important to secure durability that can withstand long-term use. However, it is a reality that a lithium ion secondary battery having high charge and discharge capacity and having high safety and durability has not been obtained.

Japanese Patent Laid-Open No. 9-270258 Japanese Patent Laid-Open No. 2001-243948 Japanese Patent Laid-Open No. 2008-166269

An object of the present invention is to provide a non-aqueous electrolyte secondary battery capable of achieving two characteristics of high safety and durability while having a high charge and discharge capacity, and a positive electrode active material capable of realizing this non-aqueous electrolyte secondary battery. It is done.

In view of the above problems, the present inventors earnestly studied a lithium ion secondary battery and its positive electrode material capable of achieving both high safety and durability, and as a result, the aluminum-containing lithium nickel composite oxide as the positive electrode material was fine secondary particles and coarse secondary particles. It has been found that, by increasing the aluminum-containing concentration of the fine secondary particles therein than the aluminum-containing concentration of the coarse secondary particles, it has been found that high safety and durability can be achieved in a battery using this as a positive electrode material. The invention has been completed.

That is, the positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention is a lithium nickel composite oxide to which at least two or more kinds of metal elements including aluminum are added, and the fine secondary particles having an average particle diameter of 2 to 4 μm and the average particle diameter of 6 to 4 are present. Coarse secondary particles having a thickness of 15 μm, including secondary particles having an average particle diameter of 5 to 15 μm in total, and wherein the aluminum content (metal molar ratio; SA) of the fine secondary particles is the aluminum content (metal molar ratio) of the coarse secondary particles. More than LA).

The lithium nickel composite oxide is represented by the formula: Li _w Ni _{1- xyz} Co _x Al _y M _z O ₂ (wherein M is at least one element selected from Mn, Ti, Ca, Mg, Nb, Si, Zr and W). , 0.99≤w≤1.10, 0.05≤x≤0.30, 0.01≤y≤0.1, 0≤z≤0.01), and the aluminum content (SA) of the fine secondary particles and the aluminum of the coarse secondary particles It is preferable that the ratio (aluminum concentration ratio; SA / LA) of content LA exists in the range of 1.12-2.6, and it is especially preferable that it is 1.2 or more.

Moreover, it is preferable that the particle size distribution by a laser diffraction scattering method measurement exists in the range of 0.5-6 micrometers in the said fine secondary particle, and exists in the range of 3-25 micrometers in the said coarse secondary particle, and the said fine secondary particle mixes It is preferable that the ratio to be 1 to 10% by volume ratio with respect to the said lithium nickel complex oxide whole.

Moreover, the manufacturing method of the positive electrode active material for nonaqueous electrolyte secondary batteries of this invention adds and mixes an aluminum compound to a nickel composite hydroxide, oxidizes and roasts the obtained aluminum containing nickel composite hydroxide, and a lithium compound to the obtained aluminum containing nickel composite oxide. In the method of further adding and mixing the mixture, and calcining the obtained mixture to obtain a positive electrode active material for a non-aqueous electrolyte secondary battery containing a lithium nickel composite oxide, in the step of adding and mixing an aluminum compound to the nickel composite hydroxide, the average particle diameter The aluminum content of the fine secondary particles (metal molar ratio; SA) in each of the nickel composite hydroxide containing the fine secondary particles having 2 to 4 μm and the coarse secondary particles having the coarse secondary particles having an average particle diameter of 6 to 15 μm. Aluminum content (metal molar ratio) of this said coarse secondary particle; The aluminum compound is added and mixed so as to be larger than LA), thereby obtaining the aluminum-containing nickel composite oxide containing secondary particles having an average particle diameter of 5 to 15 µm.

The non-aqueous electrolyte secondary battery of the present invention is also characterized in that the above-mentioned positive electrode active material for non-aqueous electrolyte secondary batteries is used as the positive electrode material.

The positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention is a lithium nickel composite oxide having high charge and discharge characteristics, and when used as a positive electrode material of a lithium ion secondary battery, high safety and durability in the battery can be simultaneously achieved. have. The lithium ion secondary battery using the positive electrode active material of the present invention as a positive electrode material can continue to be used for a long time even when applied to a vehicle-mounted power source represented by a hybrid vehicle or an electric vehicle, and can maintain high safety.

As described above, the positive electrode active material for the non-aqueous electrolyte secondary battery of the present invention and the non-aqueous electrolyte secondary battery using the same have a high capacity and can be suitably used for large secondary batteries such as automobile mounts requiring high safety and durability. His industrial value is very large.

(1) positive electrode active material

The positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention is a lithium nickel composite oxide to which at least two or more kinds of metal elements including aluminum are added, and fine secondary particles having an average particle diameter of 2 to 4 μm and a coarse particle having an average particle diameter of 6 to 15 μm. It includes secondary particles having an average particle diameter of 5 to 15 µm in which secondary particles are mixed, and the aluminum content (SA) of the fine secondary particles is larger than the aluminum content (LA) of the coarse secondary particles. In addition, aluminum content is the value which showed the aluminum amount with respect to the total amount of metals other than lithium contained in each secondary particle in metal molar ratio.

In the lithium nickel composite oxide (LNO) used as the positive electrode active material for a non-aqueous electrolyte secondary battery, improvement by various additive elements is examined in order to improve safety and durability. If the additional element diffuses uniformly in the crystal of LNO, the crystal structure of the LNO is stabilized. However, increasing the additive element in order to improve the safety reduces the amount of nickel which contributes to the redox reaction together with the charge and discharge reactions, resulting in a significant decrease in battery capacity, which is the most important battery performance. Therefore, it is necessary to make the addition amount of an additional element as small as possible.

In addition, the powdery lithium nickel composite oxide usually has some expansion in the particle size distribution. In other words, the powdery lithium nickel composite oxide can be said to be a mixture of fine secondary particles and coarse secondary particles. Since fine secondary particles have more surface area per volume than coarse secondary particles, the insertion and desorption reaction of Li ions due to charging and discharging in the battery occurs on the surface of the lithium metal composite oxide particles, so the reaction is finer than coarse secondary particles. It is thought that secondary particles are easier to use. Therefore, compared with the coarse secondary particle, a fine secondary particle becomes large and deteriorates first, and it degrades safety and durability of a battery.

Therefore, it can be said that safety and durability as a battery are also improved by improving the durability of the fine secondary particle contained in a lithium nickel composite oxide.

When a sufficient amount of additional elements are added to improve safety and durability, if the entire lithium nickel composite oxide is made into a uniform composition, its battery capacity is greatly reduced. On the other hand, by increasing the addition amount of the additional element to the fine secondary particles, which particularly need to improve the safety and durability, the amount of addition of the additional element as the whole lithium nickel composite oxide is suppressed, while ensuring sufficient battery capacity and fine secondary particles. It is possible to stabilize the crystal structure of and to make both the safety and durability of the entire lithium nickel composite oxide compatible. The positive electrode active material of the present invention is made based on this knowledge.

That is, in the positive electrode active material of the present invention, the aluminum content (SA) in the fine secondary particles having an average particle diameter of 2 to 4 µm is larger than the aluminum content (LA) in the coarse secondary particles having an average particle diameter of 6 to 15 µm. There is an important significance.

Aluminum is effective for improving the safety and durability of lithium nickel composite oxides. Therefore, the positive electrode active material of this invention is a lithium metal composite oxide to which at least 2 or more types of metal elements containing aluminum were added, and by making the aluminum content of a fine secondary particle more, safety and durability as a whole lithium nickel composite oxide are improved. It can be improved.

The positive electrode active material of the present invention contains secondary particles having an average particle diameter of 5 to 15 μm as a whole, fine secondary particles having an average particle diameter of 2 to 4 μm, and a coarse particle having an average particle diameter of 6 to 15 μm, preferably 6 to 10 μm. Secondary particles are mixed. If the average particle diameter of the fine secondary particles is less than 2 µm, the addition of aluminum of the fine secondary particles does not sufficiently improve the safety and durability, and does not reflect the improvement of the safety and durability of the entire positive electrode active material. In addition, when the average particle diameter of the fine secondary particles exceeds 4 μm, the ratio of the fine secondary particles to the total lithium metal composite oxide increases, so that the particles containing a lot of aluminum increase, so that sufficient battery capacity is provided as the positive electrode active material. Not obtained.

On the other hand, if the average particle diameter of the coarse secondary particles is less than 6 µm, the particles having a small addition of aluminum increase despite the small particle diameter, so that sufficient safety and durability are not obtained. In addition, when the average particle diameter of the coarse secondary particles exceeds less than 15 µm, the fine secondary particles increase in order to make the average particle diameter as a whole 5 to 15 µm, so that sufficient battery capacity as a positive electrode active material is not obtained. .

It is preferable that ratio (aluminum concentration ratio; SA / LA) of aluminum content SA of the said fine secondary particle and aluminum content LA of the said coarse secondary particle is 1.12-2.6. When the aluminum concentration ratio SA / LA is less than 1.12, the difference in the amount of aluminum added to the fine secondary particles and the coarse secondary particles is small, and when the current flows in a large amount such as overcharge or short circuit, the fine secondary particles first release Li to be determined. The structure becomes unstable. In addition, the decomposition accompanied with the release of oxygen occurs in the fine secondary particles whose structure is unstable, whereby thermal runaway occurs, which increases the possibility of causing a decrease in thermal stability. Therefore, when aluminum concentration ratio SA / LA is less than 1.12, sufficient safety and battery capacity may not be obtained as a positive electrode active material. Moreover, in order to acquire more sufficient safety and battery capacity, it is especially preferable that SA / LA is 1.2 or more. On the other hand, when SA / LA exceeds 2.6, since the amount of aluminum added to the coarse secondary particles becomes too small, the safety and durability of the coarse secondary particles are lowered, and sufficient safety and durability as a positive electrode active material are not obtained. There is a case.

In the positive electrode active material of the present invention, the particle size distribution by laser scattering method measurement is preferably in the range of 0.5 to 6 µm in the fine secondary particles, and in the range of 3 to 25 µm in the coarse secondary particles. Even if the average particle diameter is in the range of 2 to 4 μm, when the particle size distribution of the fine secondary particles widens to less than 0.5 μm, even if aluminum is added to the particles having a particle size of less than 0.5 μm, the safety and durability are not sufficiently improved, and the positive electrode active material In some cases, the safety and the durability as well are not sufficiently improved. On the other hand, when the particle size distribution of the fine secondary particles becomes wider than 6 µm, the proportion of the fine secondary particles with a large amount of aluminum added increases, so that sufficient battery capacity may not be obtained as the positive electrode active material.

In addition, even if the average particle diameter of the coarse secondary particles is in the range of 6 to 15 µm, when the particle size distribution of the coarse secondary particles is widened to less than 3 µm, fine secondary particles having a small amount of aluminum added are present, and the fine particles deteriorate first and thus Durability may be reduced. On the other hand, when it becomes wider than less than 25 micrometers, the specific surface area of a positive electrode active material may fall, and sufficient battery capacity may not be obtained.

Moreover, in the positive electrode active material of this invention, it is preferable that the ratio which the said fine secondary particle mixes is 1 to 10% by volume ratio with respect to the said lithium metal composite oxide whole. When the said mixing ratio is less than 1% by volume ratio, the average particle diameter may exceed 15 micrometers as the whole positive electrode active material. Moreover, when the ratio to mix exceeds 10% by volume ratio, since the particle | grains with many aluminum addition amounts increase, sufficient battery capacity may not be obtained as a positive electrode active material.

The positive electrode active material of the present invention is a lithium nickel composite oxide to which at least two or more kinds of metal elements including aluminum are added to improve safety and durability, and in particular, to improve durability and to obtain a high capacity, the composition thereof is represented by the formula: Li _w Ni _{1- xyz} Co _x Al _y M _z O ₂ (wherein M is at least one element selected from Mn, Ti, Ca, Mg, Nb, Si, Zr and W, 0.99 ≦ w ≦ 1.10, 0.05 It is preferable to set it as the lithium nickel complex oxide represented by <= x <= 0.30, 0.01 <= y <= 0.1, 0 <= z <0.01). Hereinafter, each additional element is explained in full detail.

a) Co

Cobalt (Co) is an addition element that contributes to improvement of cycle characteristics. When the value of x which shows the addition amount is smaller than 0.05, sufficient cycling characteristics may not be acquired and capacity retention may also fall. On the other hand, when the value of x exceeds 0.3, the fall of initial stage discharge capacity may become large. In addition, the amount of expensive Co increases, which may be undesirable from the viewpoint of cost.

b) Al

Aluminum (Al) is an additive element having an effect on improving safety and durability. When the value of y which shows the addition amount is less than 0.01, there is a possibility that addition amount is too small and an addition effect may not fully be acquired. On the other hand, if the value of y exceeds 0.1, the safety and durability are improved depending on the amount added, but since Al itself does not contribute to the charge / discharge reaction, the charge / discharge capacity of the battery is lowered and the energy density is lowered, which is not preferable. . Considering the balance between charge and discharge capacity, safety and durability, it can be said that about 0.04 is preferable.

Further, for the fine secondary particles and the coarse secondary particles, y is 0.03 to 0.1 for the fine secondary particles and y for the coarse secondary particles within a range where the SA / LA is 1.2 to 2.6. It is preferable to become 0.01-0.05.

c) M

The additional element M is not particularly limited, but may be an element that is effective in improving cycle characteristics, safety, and reducing reaction resistance, but at least 1 selected from Mn, Ti, Ca, Mg, Nb, Si, Zr, and W It is preferable to set it as an element of a species. In particular, addition of Ca or Mg, or both, has a great effect on improving safety. When the additive element M is uniformly diffused in the crystal in the lithium nickel composite oxide, the crystal structure in the lithium nickel composite oxide is stabilized. Thereby, the thermal stability of a non-aqueous electrolyte secondary battery can also be improved.

Although addition of M is arbitrary, when adding, it is preferable that the value of z which shows the addition amount becomes 0.0003 or more. If the value of z is less than 0.0003, the effect of stabilization of the crystal structure is not sufficiently recognized. On the other hand, if z is more than 0.01, the stabilization of the crystal structure is further achieved, but it is not preferable because the decrease in initial discharge capacity becomes large.

In the present invention, the lithium nickel composite oxide is in the form of spherical secondary particles in which primary particles are aggregated, and the average particle diameter of the secondary particles as a whole is preferably 5 to 15 µm. When the average particle diameter is less than 5 µm, the tap density is lowered, and the battery capacity per unit mass may be lowered. On the other hand, when the average particle diameter exceeds 15 µm, the specific surface area becomes small, the reaction area is insufficient, and the output characteristics are lowered, which is not preferable. In addition, the 50% volume integrated value by the particle size distribution measuring apparatus of a laser scattering system is used for the measurement of the average particle diameter in this invention.

(2) Method of producing a positive electrode active material

For the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention, the lithium nickel composite oxide is represented by the formula: Li _w Ni _{1- xyz} Co _x Al _y M _z O ₂ (wherein M is Mn, Ti, Ca, As an example, a case is represented by at least one element selected from Mg, Nb, Si, Zr and W, 0.99 ≦ w ≦ 1.10, 0.05 ≦ x ≦ 0.30, 0.01 ≦ y ≦ 0.1, 0 ≦ z ≦ 0.01). do. In addition, this invention is not specifically limited to the manufacturing method described in this specification, The person skilled in the art can implement in the form which performed various changes and improvement based on the knowledge from the following description.

2-1) Preparation of Nickel Composite Hydroxide

First, nickel composite hydroxides are prepared. Nickel composite hydroxides can be prepared by various known techniques.

For example, the pH is adjusted by adding an aqueous alkali solution to an aqueous solution containing nickel salts, cobalt salts, and M metal salts blended at a predetermined ratio, and co-precipitating the hydroxides of Ni, Co, and M to form a chemical formula: Ni _{1 -xy-} A nickel composite hydroxide represented by _z Co _x M _z (OH) ₂ (y is an Al content) is obtained. The ratio of Ni, Co and M in the aqueous solution is determined according to the composition of the lithium nickel composite oxide to be finally obtained. As coprecipitation conditions, it is preferable to make pH measured based on liquid temperature of 50-80 degreeC and liquid temperature of 25 degreeC into 10.0-13.5, and complexing agents, such as an ammonium ion supply body, can also be added to aqueous solution.

The nickel composite hydroxide obtained by the coprecipitation method has a form of secondary particles in which primary particles are agglomerated, but in this case, the shape of the secondary particles is spherical, and it is preferable to adjust so that the average particle diameter of the entire secondary particles becomes 5 to 15 µm. About the shape and average particle diameter of particle | grains, it can adjust by controlling the mixing speed and coprecipitation conditions of the said aqueous solution and aqueous alkali solution.

Filtration, washing with water and drying are performed on the obtained nickel cobalt composite hydroxide, but these treatments may be a conventional method.

In addition, it is also possible to employ a method of mixing raw material hydroxides or oxides of the respective additional elements.

In this case, the fine secondary particles and the coarse secondary particles are classified before the addition of Al, which is a subsequent step, but the nickel composite hydroxide having an average particle diameter of 2 to 4 µm and the nickel having an average particle diameter of 6 to 15 µm are used in the production process of the nickel composite hydroxide. The composite hydroxides can be produced separately and each can be used as fine secondary particles and coarse secondary particles.

2-2) Al addition

An aluminum compound is adsorbed on the surface of the obtained nickel composite hydroxide to obtain an aluminum-containing nickel composite hydroxide represented by the chemical formula: Ni _{1 -xy- z} Co _x Al _y M _z (OH) ₂ .

First, in the case where the fine secondary particles and the coarse secondary particles are not produced separately, the obtained nickel composite hydroxide is classified and fine secondary particles having an average particle diameter of 2 to 4 µm and coarse secondary particles having an average particle diameter of 6 to 15 µm. To separate.

Next, in consideration of the mixing ratio of the fine secondary particles and the coarse secondary particles, the aluminum concentration ratio (SA / LA) of the fine secondary particles and the coarse secondary particles is 1.2 to 2.6, and the total aluminum content (y value) is 0.01 to 0.1. The aluminum compound is adsorbed to each nickel composite hydroxide.

Adsorption is performed by adding the aqueous solution containing an aluminum compound, making the said nickel composite hydroxide particle into a slurry, and stirring a slurry, adjusting pH. Furthermore, after mixing the aqueous solution containing the aluminum salt of a desired density | concentration with a slurry, pH can be adjusted and an aluminum compound can be made to adsorb | suck to the particle surface of a nickel composite hydroxide.

Moreover, aluminum salts, such as the alkali salt of aluminic acid, are mentioned as an aluminum compound. As an alkali salt of aluminic acid, sodium aluminate and potassium aluminate are preferable. By using an alkali salt of aluminic acid, aluminum hydroxide produced by neutralization is adsorbed to the surface of the nickel composite hydroxide suspended in water, but aluminum hydroxide produced and precipitated by this neutralization has relatively good filterability, and washing after filtration Even when the aluminum hydroxide is not separated from the nickel composite hydroxide, aluminum hydroxide can be uniformly dispersed around the nickel composite hydroxide (see Japanese Patent Laid-Open No. Hei 11-16572).

After addition, both secondary particles are mixed and finally adjusted to the ratio of aluminum in the lithium nickel composite oxide to be obtained. Usually, since almost full concentration precipitates as a compound (aluminum hydroxide) from an aluminum salt, the quantity of the aluminum salt added from the ratio of aluminum in a lithium nickel complex oxide can be calculated | required.

After aluminum hydroxide is made to adsorb | suck to the surface of the particle | grains of a nickel composite hydroxide, it performs filtration, water washing, and drying. Filtration, washing with water and drying can be performed by the same method as the manufacture of nickel composite hydroxide.

2-3) Oxidation roasting

Next, the nickel composite hydroxide which adsorbed aluminum hydroxide on the surface is oxidized and roasted. By oxidizing and roasting, the reactivity with Li can be improved, the reaction can be sufficiently advanced in a short time, and the productivity is improved.

Moreover, 650-750 degreeC is preferable and, as for the roasting oxide temperature, 700-750 degreeC is more preferable. If it is less than 650 ° C, the oxide film formed on the surface is not sufficient, and if it exceeds 750 ° C, the surface area is excessively reduced and the reactivity with Li decreases, which is not preferable.

The atmosphere of the roasting oxide is not a problem as long as it is a non-reducing atmosphere, and an atmospheric atmosphere or an oxygen atmosphere is preferable. The oxidation roasting time and the furnace to be treated are not particularly limited and can be appropriately set depending on the amount to be treated and the roasting temperature. For example, the roasting time is preferably 1 hour or more, more preferably 3 to 15 hours. If it is less than 1 hour, the conversion from hydroxide to oxide may not be sufficiently performed. If it is less than 3 hours, the crystallinity of the nickel composite oxide may not be improved and thermal stability may not be sufficiently obtained. Moreover, the furnace used for roasting oxidation is not specifically limited, Although it can be heated in air stream, the electric furnace without gas generation is preferable, and a batch or continuous furnace can be used.

2-4) Addition of Li

In order to add lithium (Li), the nickel composite oxide obtained by roasting oxide is mixed with a lithium compound to obtain a mixture. The amount of the lithium compound to be mixed is finally the chemical formula to be obtained: Li _w Ni _{1- xy- z} Co _x Al _y M _z O ₂ (wherein M is Mn, Ti, Ca, Mg, Nb, Si, Zr and At least one element selected from W, 0.99 ≦ w ≦ 1.10, 0.05 ≦ x ≦ 0.30, 0.01 ≦ y ≦ 0.1, and 0 ≦ z ≦ 0.01) is appropriately determined from the composition of the lithium metal composite oxide.

Although lithium salts, such as lithium nitrate and lithium hydroxide, can be used as a lithium compound to mix, it is preferable to use lithium hydroxide especially.

The mixing may be a dry mixer or a mixing granulator such as a V blender, a spartan loser, a radig mixer, a Julia mixer, or a vertical granulator, and is preferably performed in a suitable time range for uniform mixing.

2-5) firing

The mixture is calcined to obtain a lithium nickel composite oxide which is a positive electrode active material for a non-aqueous electrolyte secondary battery. Here, it is preferable to set baking temperature to 650-800 degreeC, and it is more preferable to set it to 700-800 degreeC. The holding time at the highest achieved temperature is not limited as long as the reaction progresses can be obtained, and is preferably about 1 to 10 hours. Moreover, as an atmosphere at the time of baking, it is preferable to set it as oxidative atmosphere, such as oxygen atmosphere.

When the firing temperature is less than 650 ° C, the reaction with the lithium compound does not proceed sufficiently, and it becomes difficult to synthesize a lithium nickel composite oxide having good crystallinity in the layered structure. On the other hand, when it exceeds 800 degreeC, cation mixing starts to generate | occur | produce, and it is unpreferable since other metal ions begin to mix in Li site and battery characteristic falls.

(3) Non-aqueous electrolyte secondary battery

The non-aqueous electrolyte secondary battery of the present invention contains a positive electrode, a negative electrode, a non-aqueous electrolyte, and the like, and is composed of the same components as a general non-aqueous electrolyte secondary battery. In addition, the embodiment described below is only an illustration, The non-aqueous electrolyte secondary battery of this invention is not specifically limited to embodiment described in this specification, The person skilled in the art can change variously based on the knowledge from the following description. It is possible to apply the form which changed and improved. In addition, the use of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited.

(a) Positive electrode

The positive electrode of a non-aqueous electrolyte secondary battery is produced as follows, using the positive electrode active material for non-aqueous electrolyte secondary batteries obtained as mentioned above as a positive electrode material, for example.

First, a powdery positive electrode active material, a conductive material, and a binder are mixed, an aqueous solvent is added, and this is kneaded to prepare a positive electrode mixture aqueous paste. The mixing ratio of each of the positive electrode mixture aqueous pastes is also an important factor in determining the performance of the non-aqueous electrolyte secondary battery. When the total mass of solid content of the positive electrode mixture excluding the aqueous solvent was 100 parts by mass, the content of the positive electrode active material was 80 to 95 parts by mass, and the content of the conductive material was 2 to 15, similar to the positive electrode of a general nonaqueous electrolyte secondary battery. It is preferable to set it as mass part and to make content rate of a binder 1-20 mass parts.

The obtained positive electrode mixture paste is applied to the surface of an aluminum foil current collector, for example, and dried to scatter the solvent. As needed, in order to raise electrode density, it may pressurize with a roll press etc. In this manner, a sheet-shaped positive electrode can be produced. The sheet-like positive electrode can be cut to an appropriate size according to the intended battery, and can be used for production of the battery.

As a conductive agent in the production of the positive electrode, for example, graphite (natural graphite, artificial graphite, expanded graphite, etc.), carbon black-based materials such as acetylene black, Ketjen black, and the like can be used.

The binder plays a role of binding the active material particles, and a water-soluble polymer material which is dissolved in water is preferable. Such polymer materials include carboxymethyl cellulose (CMC), methyl cellulose (MC), cellulose acetate cellulose (CAP), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl methyl cellulose phthalate (HPMCP), and polyvinyl alcohol, which are hydrophilic polymers. (PVA), polyethylene oxide (PEO), etc. are mentioned. In addition, polymer materials dispersed in water (water dispersible) can also be preferably used. For example, fluorine resin, such as polytetrafluoroethylene (PTFE), tetrafluoroethylene- perfluoroalkyl vinyl ether copolymer (FEP), and ethylene-tetrafluoroethylene copolymer (ETFE), vinyl acetate copolymer And rubbers such as styrene-butadiene block copolymer (SBR), acrylic acid-formed SBR resin (SBR-based latex), and gum arabic. Of these, the use of fluorine-based resins such as PTFE is preferable.

Aqueous paste can be adjusted by adding the positive electrode active material of this invention and additives, such as the above-mentioned electrically conductive agent and binder to a suitable aqueous solvent, disperse | distributing, or dissolving, and mixing.

The adjusted paste is applied to the positive electrode current collector, and the aqueous solvent is evaporated to dryness and then compressed. Typically, a paste for forming an active material layer can be applied to the surface of the current collector with a predetermined thickness using a suitable coating device (coater). The thickness which apply | coats the said paste is not specifically limited, According to the shape and use of a positive electrode and a battery, it can be made to differ suitably. For example, it is apply | coated to the surface of the thin current collector which is about 10-30 micrometers in thickness so that the thickness after drying may be about 5-100 micrometers. After coating, the coating material may be dried using a suitable dryer to form an active material layer having a predetermined thickness on the surface of the current collector. The positive electrode sheet of the target thickness can be obtained by pressing the positive electrode thus obtained as desired.

(b) Negative electrode

In the negative electrode, a binder is mixed with a negative electrode active material capable of occluding and desorbing lithium ions, such as metallic lithium, a lithium alloy, and the like, and a suitable negative electrode mixture is applied to the surface of the metal foil current collector such as copper to form a paste. And compressed and dried to increase the electrode density as necessary.

As the negative electrode active material, any carbon material of, for example, natural graphite, artificial graphite, non-graphitized carbonaceous material, digraphitized carbonaceous material, or a structure having a combination thereof is preferably used. Can be.

(c) Separator

A separator is interposed between the positive electrode and the negative electrode. The separator separates the positive electrode and the negative electrode and holds the electrolyte, and may be a thin film such as polyethylene or polypropylene, and a film having a large number of minute pores.

(d) Non-aqueous liquid electrolyte

The non-aqueous electrolyte solution is obtained by dissolving a lithium salt as a supporting salt in an organic solvent.

Examples of the organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and trifluoropropylene carbonate, and also diethyl carbonate, dimethyl carbonate and ethyl methyl carbonate. , Chain carbonates such as dipropyl carbonate, ether compounds such as tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxyethane, sulfur compounds such as ethylmethyl sulfone and butanesultone, triethyl phosphate and triphosphate It can be used individually by 1 type selected from phosphorus compounds, such as octyl, or 2 or more types.

As the supporting salt, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiN (CF ₃ SO ₂ ) ₂ , or a combination salt thereof can be used. The concentration of the supporting salt may be the same as the electrolyte used in the conventional lithium ion secondary battery, and there is no particular limitation. An electrolyte solution containing a suitable lithium compound (supporting salt) at a concentration of about 0.1 mol / L to about 5 mol / L can be used.

In addition, the non-aqueous electrolyte solution may contain a radical trapping agent, a surfactant, a flame retardant, and the like.

(e) the shape and configuration of the battery

The shape of the non-aqueous electrolyte secondary battery of the present invention composed of the positive electrode, the negative electrode, the separator, and the non-aqueous electrolyte solution described above can be various, such as cylindrical or stacked type.

In any case of adopting a shape, the positive electrode and the negative electrode are laminated through a separator to form an electrode body, and the obtained electrode body is impregnated with a non-aqueous electrolyte solution, between the positive electrode current collector and the positive electrode terminal communicating with the outside, and between the negative electrode current collector and the external device. Between the negative electrode terminals connected to each other is connected using a current collector lead or the like, and sealed in a battery case to complete a non-aqueous electrolyte secondary battery.

[Example]

Hereinafter, the present invention will be described in detail using examples and comparative examples. In addition, the measurement of an average particle diameter and particle size distribution was measured using the laser scattering particle size measuring apparatus (Microtrack HRA by Nikki Corporation), and used as MV value in 50% of volume integration as average particle diameter. In addition, composition analysis was performed by ICP emission analysis using 725-ES by Varian Corporation as an ICP emission analysis apparatus.

(Example 1)

A mixed aqueous solution having a concentration of 1.8 mol / L dissolved in water such that nickel sulfate and cobalt sulfate in a molar ratio of Ni: Co = 0.83: 0.17 using a reactor for continuous crystallization having an overflow piping at the top thereof, and a neutralizing agent 25 The aqueous sodium hydroxide solution and 25% aqueous ammonia were continuously added at a constant flow rate into the reactor while maintaining a constant value of 12.0 at a pH value measured at a liquid temperature of 40 ° C and a liquid pH of 25 ° C. Crystallization was performed by the method of collect | recovering the flowing slurry continuously. The average residence time in the tank was set to 20 hours, after the continuous tank became equilibrium, the slurry was recovered, solid-liquid separated, and the crystallized substance of the nickel composite hydroxide was obtained.

The obtained nickel composite hydroxide was classified with an elbow jet classifier (manufactured by Matsubo, Co., Ltd.), and separated into fine secondary particles and coarse secondary particles. As the ratio, 96.5 volume% of coarse secondary particles having a range of 3.0 to 11 μm of fine secondary particles having a particle size distribution of 1.0 to 5.0 μm at an average particle size of 2.58 μm and a particle size distribution of 3.0 to 11 μm at an average particle diameter of 8.45 μm. .

First, while adding the hydroxide of the coarse secondary particles in water and adding NaAlO ₂ (made by Wako Junyaku Kogyo Co., Ltd., Reagent Express) in a molar ratio to Al / (Ni + Co + Al) = 0.039, The sulfuric acid was used to neutralize pH 9.5 as the target value. The composition of the post-neutralization hydroxide _{Ni 0 .81 Co 0 .151 Al 0} .039 (OH) ₂ was.

Then, the and the hydroxide of the fine secondary particles stirring it in water, NaAlO ₂ such that Al / (Ni + Co + Al) = 0.054 in molar ratio was added to (Wako Junya packed Kogyo Co., Ltd., reagent grade), The sulfuric acid was used to neutralize pH 9.5 as the target value. The composition of the post-neutralization hydroxide _{Ni 0 .802 Co 0 .144 Al 0} .054 (OH) ₂ was.

The ratio (aluminum concentration ratio; SA / LA) of the aluminum content contained in the fine secondary particles and the aluminum content contained in the coarse secondary particles was 1.38.

The hydroxide after mixing was oxidized and roasted for 6 hours at 700 ° C. in an air atmosphere using an electric furnace (ADVANTEC manufactured, electric muffle furnace, FUM373). The obtained oxide and lithium hydroxide were combined at a molar ratio of Li / (Ni + Co + Al) = 1.06, and mixed using a shaker mixer apparatus (TURBULA TypeT2C manufactured by WAB) to obtain a mixture.

Further, using this electric furnace, the mixture was calcined at 730 ° C. for 7 hours in an oxygen atmosphere to obtain a positive electrode active material.

The composition of the positive electrode active material thus obtained _{Li 1 .06 Ni 0 .81 Co 0} .1505 Al 0 _.0395 was O _2. In addition, the average particle diameter and particle size range of the fine secondary particles of the obtained positive electrode active material, the average particle size and particle size range of the coarse secondary particles, and the average particle diameter of the whole are 2.56 μm, 1.0 to 5.0 μm, 8.45 μm, 3.0 to 11.0 μm, respectively. It was 8.34 micrometers, and aluminum concentration ratio (SA / LA) of the fine secondary particle and the coarse secondary particle was 1.38.

Moreover, using each positive electrode active material, the cylindrical 18650 type lithium secondary battery was produced as follows, and durability was measured.

The positive electrode active material, acetylene black as a conductive agent, carboxymethyl cellulose as a water-soluble binder, and polytetrafluoroethylene fine particles as a water-dispersible binder are weighed so that the mass% ratio of these materials is 88: 10: 1: 1, It added to ion-exchange water so that solid content ratio of material might be 54 mass%. Subsequently, it mixed for 50 minutes with the planetary mixer, and produced the paste for positive electrode active material layer formation.

The prepared aqueous paste is applied to both sides of an aluminum foil having a thickness of about 15 μm as a positive electrode current collector so that the total coating amount is about 9.5 g / cm ² , and the moisture in the paste is dried to increase the sheet shape with a roller press, and the layer thickness is increased. It adjusted to the thickness of 60 micrometers, and produced the positive electrode sheet for lithium secondary batteries.

Subsequently, the negative electrode active material made of graphite and styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as binders are mixed with ion-exchange water so that the mass% ratio of these materials is 98: 1: 1, and the negative electrode active material A layer forming paste was produced. Further, the total coating amount of such paste was applied to both surfaces of a copper foil having a thickness of about 10 μm as a negative electrode current collector so as to be about 9.0 g / cm ² , and the moisture in the paste was dried to increase the sheet shape with a roller press, and the layer thickness was increased. It adjusted to the thickness of 60 micrometers, and produced the negative electrode sheet for lithium secondary batteries.

The obtained positive electrode sheet and negative electrode sheet were laminated together with two porous polyethylene sheets, and this laminated sheet was wound up to produce a wound electrode structure. This electrode structure was accommodated together with electrolyte solution in the container, and the cylindrical lithium ion secondary battery of diameter 18mm and height 65mm was produced. As the electrolyte solution, a nonaqueous electrolyte solution in which support salt LiPF ₆ was dissolved in a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) in a volume ratio of 1 mol / L at a concentration of 1 mol / L was used. Thus, the lithium ion secondary battery of Example 1 was produced.

In addition, a test lithium ion secondary battery was constructed by charging to 4.1 V at a charge current rate of 1/3 C as a conditioning treatment.

In order to investigate the cycle characteristics of the obtained battery, 500 cycles of charging and discharging were repeated under the conditions of a potential width of 3.0 V to 4.1 V, a current rate of 1 C, and a temperature of 60 ° C., and then discharged at a capacity ratio with an initial discharge capacity of 100. It was 89% when the capacity retention ratio was calculated. In addition, each measured value with respect to a positive electrode active material is shown in Table 1 with the calculated value of discharge capacity retention rate.

(Example 2)

A positive electrode active material was obtained in the same manner as in Example 1 except that the aluminum content added to the fine secondary particles was 0.098 in a molar ratio. The composition of the positive electrode active material thus obtained _{Li 1 .06 Ni 0 .808 Co 0} .151 Al 0 was _.041 O _2. In addition, the average particle diameter and particle size range of the fine secondary particles of the obtained positive electrode active material, the average particle diameter and particle size range of the coarse secondary particles, and the average particle diameter of the whole are 2.62 μm, 1.0 to 5.0 μm, 8.42 μm, 3.0 to 11.0 μm, respectively. It was 8.32 micrometers, and aluminum concentration ratio (SA / LA) of the fine secondary particle and the coarse secondary particle was 2.51. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 92%.

(Example 3)

A positive electrode active material was obtained in the same manner as in Example 1 except that the aluminum content added to the fine secondary particles was 0.047 in a molar ratio. The composition of the positive electrode active material thus obtained was Li _{1 .06 Ni 0 .81 Co 0 .151 Al} 0 .039 O 2. In addition, the average particle diameter and particle size range of the fine secondary particles of the obtained positive electrode active material, the average particle diameter and particle size range of the coarse secondary particles, and the average particle diameter of the whole are 2.51 μm, 1.0 to 5.0 μm, 8.43 μm, 3.0 to 11.0 μm, respectively. It was 8.37 micrometers, and aluminum concentration ratio (SA / LA) of the fine secondary particle and the coarse secondary particle was 1.21. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 88%.

(Example 4)

The particle size distribution ranges from 1.7% by volume of the fine secondary particles having a particle size distribution of 1 μm to 3 μm at an average particle size of 2.06 μm and an average particle diameter of 8.52 μm with varying conditions for separation of the fine secondary particles and the coarse secondary particles of the hydroxide. A positive electrode active material was obtained in the same manner as in Example 1 except that the coarse secondary particles having a thickness of 3 µm to 25 µm were 98.3% by volume. The composition of the positive electrode active material thus obtained was Li _{1 .06 Ni 0 .817 Co 0 .144 Al} 0 .039 O 2. In addition, the average particle diameter and particle size range of the fine secondary particles of the obtained positive electrode active material, the average particle diameter and particle size range of the coarse secondary particles, and the average particle diameter of the whole are 2.06 μm, 1.0 to 3.0 μm, 8.39 μm, 3.0 to 25.0 μm, respectively. It was 8.34 micrometers, and aluminum concentration ratio (SA / LA) of the fine secondary particle and the coarse secondary particle was 1.38. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 85%.

(Example 5)

The conditions of separation of the fine secondary particles and the coarse secondary particles of the hydroxide were changed, and the range of the particle size distribution was 6.3% by volume and the average particle diameter was 8.67 μm at the average particle size of 3.45 μm and the fine secondary particles having a particle size distribution of 1 μm to 5.5 μm. A positive electrode active material was obtained in the same manner as in Example 1 except that the coarse secondary particles having a thickness of 6 µm to 25 µm were 93.7% by volume. The composition of the positive electrode active material thus obtained was Li _{1 .06} Ni _{0 .81 Co 0 .15 Al 0 .04 O} 2. In addition, the average particle diameter and particle size range of the fine secondary particles of the obtained positive electrode active material, the average particle diameter and particle size range of the coarse secondary particles, and the average particle diameter of the whole are 3.45 μm, 1.0 to 5.5 μm, 8.67 μm, 6.0 to 25 μm, respectively. It was 8.32 micrometers, and aluminum ratio ratio (SA / LA) of the fine secondary particle and the coarse secondary particle was 1.38. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 92%.

(Example 6)

A positive electrode active material was obtained in the same manner as in Example 1 except that the aluminum content added to the fine secondary particles was 0.045 in a molar ratio. The composition of the positive electrode active material thus obtained was Li _{1 .06 Ni 0 .81 Co 0 .151 Al} 0 .039 O 2. In addition, the average particle diameter and particle size range of the fine secondary particles of the obtained positive electrode active material, the average particle diameter and particle size range of the coarse secondary particles, and the average particle diameter of the whole are 2.62 μm, 1.0 to 5.0 μm, 7.89 μm, 3.0 to 11.0 μm, respectively. It was 8.38 micrometers, and aluminum concentration ratio (SA / LA) of the fine secondary particle and the coarse secondary particle was 1.15. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 82%.

(Comparative Example 1)

A positive electrode active material was obtained in the same manner as in Example 1 except that Al was added so that Al / (Ni + Co + Al) = 0.039 at a molar ratio without classification. The composition of the positive electrode active material thus obtained was Li _{1 .06 Ni 0 .81 Co 0 .151 Al} 0 .039 O 2. The average particle diameter of the obtained positive electrode active material was 8.38 mu m. In addition, as a result of classification and analysis in the same manner as in Example 1, the aluminum concentration ratio (SA / LA) of the fine secondary particles and the coarse secondary particles of the positive electrode active material was 1.10. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 50%.

(Comparative Example 2)

Nickel sulfate and cobalt sulfate were added in a molar ratio of nickel and cobalt sulfate while maintaining a constant value of 12.0 as a pH value measured based on a liquid temperature of 25 ° C. using a reactor for continuous crystallization having an overflow piping at the top. Ni: Co mixed aqueous solution of concentration 1.8 mol / L dissolved in water so that: Co = 0.85: 0.15, 25% aqueous sodium hydroxide solution and 25% aqueous ammonia, and a solution in which sodium aluminate was dissolved in pure water in a molar ratio. Crystallization was performed by the general method of continuously applying a constant flow rate such that: Al = 0.81: 0.15: 0.04, and continuously recovering the overflowing slurry. After the average residence time in the tank was set to 20 hours, and the continuous tank was in equilibrium, the slurry was recovered and solid-liquid separated, thereby obtaining a crystallized composite hydroxide.

The obtained hydroxide was oxidized and roasted at 700 ° C. for 6 hours in an air atmosphere using an electric furnace (Advantech, Electric Muffle Furnace FUM373) to obtain an oxide. The obtained oxide and lithium hydroxide were combined at a molar ratio of Li / (Ni + Co + Al) = 1.06, mixed using a shaker mixer apparatus (WAB Co., Turbula TypeT2C) to obtain a mixture.

The cycle characteristics were evaluated in the same manner as in Example 1 except that the mixture was calcined at 730 ° C. for 16 hours in an oxygen atmosphere using the above-described electric furnace to obtain a positive electrode active material.

The composition of the positive electrode active material thus obtained was Li _{1 .06} Ni _{0 .81 Co 0 .15 Al 0 .04 O} 2. Moreover, it was 10.29 micrometers when the average particle diameter of the whole of the obtained positive electrode active material was calculated | required.

The obtained positive electrode active material was classified in the same manner as in Example 1, and then analyzed for each aluminum content. As a result, the aluminum concentration ratio (SA / LA) of the fine secondary particles and the coarse secondary particles was 1.02. In the same manner as in Example 1, the discharge capacity retention rate was measured and found to be 29%.

The non-aqueous electrolyte secondary battery of the present invention, which is excellent in safety and has high cycle characteristics, is suitable for power supplies for automobiles that require long-term use.

In addition, in the power supply for an electric vehicle, it is indispensable to secure the safety due to the enlargement of the battery and an expensive protection circuit for securing the higher safety. On the other hand, since the nonaqueous electrolyte secondary battery of the present invention has excellent safety, the safety of the surface is also high, and it is also suitable as a power source for electric vehicles. Moreover, the present invention can be used not only as a power source for electric vehicles driven purely with electric energy, but also as a power source for so-called hybrid vehicles used in combination with combustion engines such as gasoline engines and diesel engines.

Claims (8)

A lithium nickel composite oxide to which at least two or more kinds of metal elements including aluminum are added, including fine secondary particles having an average particle diameter of 2 to 4 µm and coarse secondary particles having an average particle diameter of 6 to 15 µm, and the total average particle diameter The particle | grains which contain this 5-15 micrometer secondary particle, the particle size distribution by a laser diffraction scattering measurement exist in the range of 0.5-6 micrometers for the said fine secondary particle, and it exists in the range of 3-25 micrometers in the said coarse secondary particle. And a ratio of the aluminum content represented by the metal mole ratio of the fine secondary particles to the aluminum content represented by the metal molar ratio of the coarse secondary particles is in the range of 1.12 to 2.6. The method of claim 1, wherein the lithium nickel composite oxide is represented by the formula: Li _w Ni _{1- xyz} Co _x Al _y M _z O ₂ (wherein M is selected from Mn, Ti, Ca, Mg, Nb, Si, Zr and W) A positive electrode active material for a non-aqueous electrolyte secondary battery represented by at least one element, 0.99 ≦ w ≦ 1.10, 0.05 ≦ x ≦ 0.30, 0.01 ≦ y ≦ 0.1, and 0 ≦ z ≦ 0.01). The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 or 2, wherein the ratio is 1.2 or more. The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 or 2, wherein the proportion of the fine secondary particles is mixed in a volume ratio of 1 to 10% with respect to the entire lithium nickel composite oxide. An aluminum compound is added and mixed to the nickel composite hydroxide, and the aluminum-containing nickel composite hydroxide obtained is oxidized and roasted, a lithium compound is further added and mixed to the obtained aluminum-containing nickel composite oxide, and the resulting mixture is calcined to obtain a lithium nickel composite oxide. In the method for obtaining a positive electrode active material for a non-aqueous electrolyte secondary battery comprising, in the step of adding and mixing an aluminum compound to the nickel composite hydroxide, the particle size distribution by the laser diffraction scattering measurement is in the range of 0.5 to 6 ㎛ and the average particle diameter Nickel composite hydroxide containing fine secondary particles having 2 to 4 μm and nickel composite containing coarse secondary particles having a particle size distribution in the range of 3 to 25 μm and an average particle diameter of 6 to 15 μm by laser diffraction scattering measurement. In each hydroxide, represented by the metal molar ratio of the coarse secondary particles Is added and mixed with the aluminum compound so that the ratio of the aluminum content represented by the metal molar ratio of the fine secondary particles to the aluminum content is within the range of 1.12 to 2.6, and includes secondary particles having an average particle diameter of 5 to 15 µm in total. The said aluminum containing nickel composite oxide is obtained, The manufacturing method of the positive electrode active material for nonaqueous electrolyte secondary batteries. A non-aqueous electrolyte secondary battery, wherein the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 or 2 is used as a positive electrode material. delete delete